How to use the exabgp.bgp.message.OUT function in exabgp

peers = match_neighbors(reactor.peers,descriptions)
			if not peers:
				self.log_failure('no neighbor matching the command : %s' % command)
				reactor.processes.answer_error(service)
				yield True
				return

			changes = self.api_vpls(command)
			if not changes:
				self.log_failure('command could not parse vpls in : %s' % command)
				reactor.processes.answer_error(service)
				yield True
				return

			for change in changes:
				change.nlri.action = OUT.ANNOUNCE
				reactor.configuration.inject_change(peers,change)
				self.log_message('vpls added to %s : %s' % (', '.join(peers) if peers else 'all peers',change.extensive()))
				yield False

			reactor.processes.answer_done(service)
		except ValueError:
			self.log_failure('issue parsing the vpls')
			reactor.processes.answer_error(service)
			yield True
		except IndexError:
			self.log_failure('issue parsing the vpls')
			reactor.processes.answer_error(service)
			yield True

def __init__ (self, rd, ve, base, offset, size):
		NLRI.__init__(self,AFI.l2vpn,SAFI.vpls)
		self.action = OUT.ANNOUNCE
		self.nexthop = None
		self.rd = rd
		self.base = base
		self.offset = offset
		self.size = size
		self.ve = ve
		self.unique = unique.next()

def __init__ (self, afi=AFI.ipv4,safi=SAFI.flow_ip,nexthop=None,rd=None):
		NLRI.__init__(self,afi,safi)
		self.rules = {}
		self.action = OUT.ANNOUNCE
		self.nexthop = IP.unpack(nexthop) if nexthop else NoIP
		self.rd = rd
		self.unique = unique.next()

def update_cache (self,change):
		if not self.cache:
			return
		family = change.nlri.family()
		index = change.index()
		if change.nlri.action == OUT.ANNOUNCE:
			self._seen.setdefault(family,{})[index] = change
		elif family in self._seen:
			self._seen[family].pop(index,None)

def ip_vpn (tokeniser,afi,safi):
	action = OUT.ANNOUNCE if tokeniser.announce else OUT.WITHDRAW
	ipmask = prefix(tokeniser)

	nlri = IPVPN(afi, safi, action)
	nlri.cidr = CIDR(ipmask.pack(),ipmask.mask)

	change = Change(
		nlri,
		Attributes()
	)

	while True:
		command = tokeniser()

		if not command:
			break

klass = last.nlri.__class__
		path_info = last.nlri.path_info
		nexthop = last.nlri.nexthop
		if klass.has_label():
			labels = last.nlri.labels
		if klass.has_rd():
			rd = last.nlri.rd

		# XXX: Looks weird to set and then set to None, check
		last.nlri.cidr.mask = cut
		last.nlri = None

		# generate the new routes
		for _ in range(number):
			# update ip to the next route, this recalculate the "ip" field of the Inet class
			nlri = klass(afi,safi,OUT.ANNOUNCE)
			nlri.cidr = CIDR(pack_int(afi,ip),cut)
			nlri.nexthop = nexthop  # nexthop can be NextHopSelf
			nlri.path_info = path_info
			# Really ugly
			if klass.has_label():
				nlri.labels = labels
			if klass.has_rd():
				nlri.rd = rd
			# next ip
			ip += increment
			yield Change(nlri,last.attributes)

	def __init__ (self, afi, safi, action=OUT.UNSET):
		MPLS.__init__(self, afi, safi, action)

	def new (cls, afi, safi, packed, mask, labels, rd, nexthop=None, action=OUT.UNSET):
		instance = cls(afi,safi,action)
		instance.cidr = CIDR(packed, mask)
		instance.labels = labels
		instance.rd = rd
		instance.nexthop = IP.create(nexthop) if nexthop else NoNextHop
		instance.action = action
		return instance

def check (change,afi):
		if not AnnouncePath.check(change,afi):
			return False

		if change.nlri.action == OUT.ANNOUNCE \
			and change.nlri.has_label() \
			and change.nlri.labels is Labels.NOLABEL:
			return False

		return True